Usually, the movable rod is implemented in the form of at least one rigid tube slidably mounted in a guide which is integral with the body of the suitcase. For example, FR 2,870,693 describes such an embodiment.
The guide or guides receiving the tube or tubes are positioned in or on the suitcase.
When positioned inside the suitcase, such an assembly represents a certain volume that is lost to the user of the suitcase.
Furthermore, whether the assembly is positioned inside or outside the suitcase, it increases the mass of the suitcase, which may be a disadvantage for the user who has to tow the suitcase and who must comply with suitcase weight limits imposed by airline companies.